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    <title>Document</title>
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<body>
    <script>
        let arr = [1,2,3,4,5,6,7,7]

        let result = arr.find((item, index, arr) => item > 5);
        console.log(result);//6

        let arr1 = [{id:1,name:"jack"},{id:2,name:"rose"},{id:3,name:"pony"}];
        console.log(arr1.find(item => item.id === 2));//{id: 2, name: "rose"}
        console.log(arr1.find(item => item.id === 99));//undefined

        console.log(arr1.findIndex(item => item.id === 2));//1
        console.log(arr1.findIndex(item => item.id === 99));//-1
    </script>
</body>
</html>